[ On Wednesday, November 5, 2003 at 08:24:12 (-0500), Walt Reed wrote: ]
> Subject: Re: [Exim] OT: Problem sending mail to verizon.net
>
> Well, I do use basic sender verification in exim:
> deny sender_domains = ! /etc/exim4/whitelist.senders
> ! verify = sender
>
> and it has helped a little with spam, but I also make sure I accept
> postmaster & abuse BEFORE such checks - something Verizon is NOT doing.
> I see no reason to accept mail from senders that I can't bounce / reply
> to.
There's no real point to doing any "active/real-time" sender address
verification by way of SMTP connections to the sender's MX, and worse
ends up causing all these problems you're complaining about.
SMTP is not a "real-time" protocol -- it's a store and forward protocol.
Attempting to implement sender address verification by way of testing
SMTP connections to the sender's MX breaks the store & forward model in
a fundamental way.
The only thing that makes sense for any kind of real-time sender address
verification is to validate the DNS for the domain in the sender
address.
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
